feat: rename project from nrd-sh to sukr

sukr = suckless + Rust. Minimal static site compiler.

- Update Cargo.toml name and description
- Update main.rs USAGE and doc comments
- Update AGENTS.md with new name, Tera architecture
- Create README.md with quick start guide

Cargo.lock

@@ -839,37 +839,6 @@ dependencies = [
  "thiserror 1.0.69",
 ]
 
-[[package]]
-name = "nrd-sh"
-version = "0.1.0"
-dependencies = [
- "gray_matter",
- "katex-rs",
- "lightningcss",
- "mermaid-rs-renderer",
- "pulldown-cmark",
- "serde",
- "tempfile",
- "tera",
- "thiserror 2.0.18",
- "toml 0.8.23",
- "tree-sitter",
- "tree-sitter-bash",
- "tree-sitter-c",
- "tree-sitter-css",
- "tree-sitter-go",
- "tree-sitter-highlight",
- "tree-sitter-html",
- "tree-sitter-javascript",
- "tree-sitter-json",
- "tree-sitter-nix",
- "tree-sitter-python",
- "tree-sitter-rust",
- "tree-sitter-typescript",
- "tree-sitter-yaml",
- "walkdir",
-]
-
 [[package]]
 name = "num-traits"
 version = "0.2.19"
@@ -1539,6 +1508,37 @@ dependencies = [
  "syn 2.0.114",
 ]
 
+[[package]]
+name = "sukr"
+version = "0.1.0"
+dependencies = [
+ "gray_matter",
+ "katex-rs",
+ "lightningcss",
+ "mermaid-rs-renderer",
+ "pulldown-cmark",
+ "serde",
+ "tempfile",
+ "tera",
+ "thiserror 2.0.18",
+ "toml 0.8.23",
+ "tree-sitter",
+ "tree-sitter-bash",
+ "tree-sitter-c",
+ "tree-sitter-css",
+ "tree-sitter-go",
+ "tree-sitter-highlight",
+ "tree-sitter-html",
+ "tree-sitter-javascript",
+ "tree-sitter-json",
+ "tree-sitter-nix",
+ "tree-sitter-python",
+ "tree-sitter-rust",
+ "tree-sitter-typescript",
+ "tree-sitter-yaml",
+ "walkdir",
+]
+
 [[package]]
 name = "syn"
 version = "1.0.109"